Effect of Some Phosphate Fertilizer Sources and Phosphate Solubilizing Microorganisms on Yield and Quality of Flame Seedless Grapes

The present study carried out during 2022 and 2023 seasons to investigate the effect of some phosphate fertilizer sources (superphosphate, triple phosphate, rock phosphate and orthophosphoric acid) either single and/ or in combination with some phosphate- solubilizing microorganisms (phosphorein, vesicular- arbuscular mycorrhizae (VA-M), phosphorein + VA-M, control (un-application on yield, cluster characters and some berry quality attributes of Flame Seedless grapes. There was a clear improvement in yield and berry quality characteristics in response to using the suitable phosphate per vine on four sources, 148.0 g RP, 277.0 g SP, 239.0 g TP and 54.0 ml OPA, in ascending order. On the other hand, the combined inoculation of phosphorein and VA- mycorrhizae had significant increases in yield and quality of berries compared with those of phosphorein or VA- mycorrhizae as single and untreated ones. The combined treatment of phosphate sources and phosphate-solubilizing microorganisms seemed to be more effective than the single one.The best results for yield and fruit quality on Flame Seedless vine were obtained with a phosphorus fertilizer of 148.0 g rock phosphate plus 10.0 g phosphoric acid plus 10.0 g VA mycorrhiza per vine / year.